Automatic switch for electric motors



(No Model.) 3 Sheets-Sheet I.

P. E. WHIPPLE, AUTOMATIC SWITCH FOR ELECTRIC MOTORS. No. 450,441. Patented Apr. 14, 1891.

(No Model.) a Sheets-Sheet 2.

' I. E. WHIPPLE.

AUTOMATIC SWITCH FOR ELECTRIC MOTORS.

No. 450,441. Patented Apr. 14, 1891.

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P. E. WHIPPLE. AUTOMATIC SWITCH FOR BLEOTRIO MOTORS. NO. 450,441. Patented Apr. 14,1891.

w 0' 3w m w 176571465 65 Jillian/Z01 UNITED STATES PATENT OFFICE.

FENNER E. XVIIIPPLE, OF PHILADELPHIA, ASSIGNOR TO THOMAS ll. DALLE' AND GEORGE A. DALLETT, BOTH OF CIIEYNEY, PENNSYLVANIA.

AUTOMATIC SWITCH FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 450,441, dated April 14, 1891. Application filed October 13, 1890. Serial F0. 367,991. (No model.)

T on whom it may concern: inafter set forth. It will be seen that as the Be it known that I, FENNER E. \VHIPPLE, a handle I) is moved upward the switch-plate citizen of the United States,and a resident of (1' will be caused to descend, seas to close the Philadelphia, Pennsylvania, have invented switch, and when the handle I) is depressed an Improved Automatic Switch for Electric the switch-plate (1 will be raised and the 5 5 Motors, &c., of which thefollowing isa speciswitch opened. fication. Each of the sheaves D D has a counter- My invention relates to that class of balance-weight D (shown by dotted lines in switches which are employed in connection Fig. l and by full lines in Fig. 5,) this conn- [0 with electric motors and are intended to apterbalance-weight tending to lnaintaiirthe 6c ply the current with gradual]y-increasing switch-plate in either of its extreme posi power, the object of my invention being to tions and preventing accidental movement provide simple and efficient mechanism for of said plate. Projecting from the block (l operating the switch-plate and for cutting out is an arm f, and through an opening in the I 5 in succession the resistanceswhich are thrown outer end of the latter passes an upright 65 into the circuit when the switch is first screw shaft F, rigidly mounted in suitable closed. T his object I attain in the manner bearings f" in the casing, the arm f being free hereinafter set forth, reference being had to to move vertically upon the screw-shaft.

the accompanying drawings, in which Supported by the arm f is aframe G, which Figure 1 is a front view of my improved has at top and bottom projecting arms with 70 switch. Fig. 2 is a plan View of the same. openings for the passage of the screw-shaft, Fig. 3 is an end View of part of the device. and projecting from this frame G are con- Figs. 4, 5, and 6 are detached views of parts tact-arms g, with spring-mounted rollers g, as of the same, Figs. 4 and 6 being on an enshown in Fig. 4t, for bearing upon the oppolarged scale. Fig. 7 is a sectional view illussite sides of the vertical series of resistance 75 trating a special feature of the invention, plates or bars 7r, mounted upon one side of and Fig. 8 is a diagram illustrating the electhe casing, or there may, if desired, be a simtrical connections of the switch. ple sliding contaetof the arms gwith the plates A represents a box or casing, in which are it, the rollers, however, being preferred.

0 mounted two shafts or spindles 13 B, the Free to turn in bearings in the frame G is 80 former carrying the sheave or pulley D, and a block II, which has a spring-pin 1? engaging the shaft B carrying a similar sheave or pulwith the thread of the screw-shaft F, this pin ley D, and around these two sheaves passes being-beveled at the upper corner, (see Fig. 6,)

a belt or band a, having a positive connecso that while it will yield radially, and thus 5 tion with each sheave-as, for instance, by permit the block ll to be raised vertically on 8 5 means of a pin a, passing through the belt the screw-shaft,it will engage with the thread and through the rim of the sheave. Secured of said screw-shaft on the descent of the block, to the belt a is a handle I), which projects and thereby cause the latter to rotate, the pin through a slot in the casing A, and is guided following the thread of the screw. The block upon a red I), mounted within said casing, so If is recessed near the top, so as to form a 90 that the handle is free to be moved vertically shoulder on, with which engages a pin m, carin order to cause movement of the belt in one ried by a slide 12, adapted to a bearing in a direction or the other. Secured, in the presbracket a, and projecting from this slide it out instance, to the opposite run of the belt is a pin p, which is engaged by the slotted from that which carries the handle I) is a upper end of a lever J hung to said bracket 5 block (I, and mounted upon the latter isa du- 02/. The slide it carries a segmental guardpleX switch-plate d, which by contact with plate 3, with a beveled lower edge, and this the two pairs of spring terminal fingers d at plate is acted upon by a spring 5, tending to the bottom of the casing A, serves to connproject the same and cause the pin on to enplete the electrical circuitinthe manner heregage with the shoulder of the block H. 1:0

Projectingfrom the side of the u pper sheave D is a pin z,and when the handle I) is'elevatcd so as to close the switch the half-turn thereby imparted-to the said sheave D causes said pin tto come in contact with the lower arm of the lever J, thereby operating the same, so as to retract the slide a and withdraw the pin m from engagement with the shoulder at of the block H.

As the previous descent of the block (1 carrying the switch-plate had removed the supportingarm f from beneath the frame G, said frame and itsblock, on the withdrawal of the pin m, will descend, the speed of this descent being retarded by reason of the fact that the spring-pin dot the block H is compelled to traverse the thread of the screw shaft F.

The frame G is connected by a system of links w to a block to at one side of the easing, the system of links being such as to freely permit the vertical movement of the frame G, and serving to convey the current from the said frame G to the block 10 as the frame moves vertically.

The electrical connections are, as described hereinafter, such that when the switch is first closed the current passes through the entire series of resistances; but as the frame G descends the resistance-plates h are successively cut out of the circuit until the rollers or 0011- tacts g finally make contact with the lowest plate of the series and are received within spring-guides 9 carried by said lower plate, so as to insure a good electrical connection at this point.

In opening the switch downward movement of the handle I), and a consequent upward movement of the block Cl, effects the lifting of the frame G and its block H, the beveled top of the latter, as it approaches the limit of its upward movement, pushing back the catch m until the latter engages with the shoulder m.

Projecting from the block H is a pin it, and if the circumferential posit-ion of the block H is such that on rising to its full extent the spring-pin i would rest upon the highest point of the thread on the screw-shaft F, and hence would not descend, the contact of the beveled lower end of the guard-plate s with said pin 00 will cause such circumferential movement of the block as will bring said pin iinto position to engage the thread. Asthe block H descends upon the screw-shaft F, there is a natural tendency to accelerated movement, and this may be corrected by a gradual diminution of the pitch of the thread of said screw, the pitch being greatest at the top and least at the bottom, as shown in Figs. 1 and 3. Such graduation of the pitch of the screw might be considered an objection, however. Hence in many cases I prefer to employ in place of' the same a form of centrifugal friction-brake. For instance, in Fig. 7 I have shown a pair of levers K hung to the block H, the depending arms of these levers being thickened or weighted and their upper arms acting upon friction-shoes 7.3, which bear upon the threads of the shaft I the latter in this case having a uniform pitch. As the block H rotates during its descent, the weighted levers are thrown outward by centrifugal force, and the shoes are therefore pressed upon the screw-shaft so as to act as friction-shoes and thus retard the descent of the block. The levers may act directly, if desired, however, and a single lever may be used instead of two; or more than two levers may be employed where circumstances warrant such use.

Various electrical connections may be devised without affecting the proper operation of the switch. In the drawings, however, the binding-posts 1 and 2 represent the terminals of the line-wires. A post 3 is intended to be connected to the field and armature of the motor, a post t to the field only, and a post 5 to the armature only. The switch-plate d has, as before stated, two portions 6 and 7, and the terminal (I has four fingers 8, 9, 10, and 11. In this case there should be an electrical connection between the post 2 and the finger 9, a fusible strip 12 being by preference interposed in this connection.

Both the block 10' and the finger 8 are intended to be connected to the post 4, while the post 1 is connected to the finger 10, the post-5 to the finger 11, and the post 5 to the lowest plate of the resistance series.

The connecting-wires are not shown in Fig. 1, as they would only tend to confuse the representation of the mechanical parts of the switch, to which my invention especially relates; but the electrical con nect-ions are shown 1 in the diagram Fig. 8.

When it is not convenient to mount the switch in the vertical position shown, the parts may be otherwise arranged, a spring in such case taking the place of gravity as a means of causing the movement of the slide G, when it is released on closing the switch.

Having thus described my invention, I claim and desire to secure by Letters Patent 1. The combination, in an electrical switch, of a pair of sheaves, a belt passing around the same, and a switch-closing plate carried by said belt, substantially as specified.

2. The combination, in an electrical switch, of a pair of sheaves and a belt passing around the same and provided with a switch-closing plate and with an operating-handle, substantially as specified.

3. The combination, in an electrical switch, of a pair of sheaves, a belt passing around the same, a switch-closing plate and operating-handle connected to said belt, and guiderods for said switch-closing plate and operating-handle, substantially as specified.

4. The combination, in an electrical switch, of a belt or band carrying the switch-closing plate with a pair of sheaves carrying said belt or band, and having counterbalanceweights tending to retain the switch-plate in its extreme posit-ions, substantially as specified.

5. The combination, in an electrical switch, of a series of resistances,a screw-shaft, and a slide traversing said resistances and having a rotatable block engaging with said screwshaft, substantially as specified.

6. The combination, in an electrical switch, of a series of resistances, a screw-shaft, a slide traversing said resistances and having a retatable block engaging with said screw-shaft,

. and a switch having an arm for acting on said slide, substantially as specified.

'7. The combination, in an electrical switch, of a series of resistances, a screw-shaft, and a slide adapted to traverse said series of resistances and having a rotatable block with spring-pin for engaging with the thread of said screw-shaft, substantially as specified.

S. The combination, in an electrical switch, of a series of resistances, a screw-shaft, a slide adapted to traverse the series of resistances and having a rotatable block engaging with said screw-shaft, a removable support or retainer for the slide, and means for withdrawing said retainer upon the closing of the switch, substantially as specified.

9. The combination, in an electrical switch, of a pair of sheaves, a belt or band carrying the switch-plate, a series of resistances, a screw-shaft, a slide adapted to traverse the series of resistances and having a rotatable block engaging with said screw-shaft, a removable retainer for said slide, a lever acting 011 said retainer, and a pin or projection on one of the sheaves for operating the lever on the closing of the switch, substantially as specified.

10. The combination, in an electrical switch,

of a series of resistances, a screw-shaft, a slide adapted to traverse the resistances and havin g a rotatable block engaging with the screwshaft, and means, substantially as described, for retarding the movement of the block on said shaft, substantially as specified.

1 1. The combination, in an electrical switch, of a series of resistances, a screw-shaft, a slide adapted to traverse said series of resistances and carrying a rotatable block engaging with said screw-shaft, and a centrifugal governor carried by said block and serving as a friction-brake to retard the movement of the same on the screw-shaft, substantiallyas specified.

12. The combination, in an electrical switch, of a series of resistances, a screw-shaft, a slide adapted to traverse said series of resistances and having a rotatable block engaging with said screw-shaft, a pin projecting from said block, and a beveled guard-plate for acting on said pin, substantially as specified.

13. The combination, in an electrical switch, of a series of resistances, a screw-shaft, a slide adapted to traverse said series of resistances and having a rotatable block engaging with said screw-shaft, and a series of links whereby current can be conveyed from the slide to a fixed block during the movement of the slide, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FENNER E. XVIIIPPLE.

Witnesses;

ISAAC BowER, ARTHUR OBRIEN. 

